The present research is designed to provide information about the perceptuomotor control of speech in normal adults. The experimental technique of selective adaptation will be used to study aspects of voice timing relations and other properties of consonant articulation after periods of repetitive listening to speech sounds. Acoustical measurements of the timing of the onset of vocal cord vibration relative to the release of plosive consonants will be carried out in an attempt to extend earlier findings over a broader range of speech sounds and in the context of a spontaneous speaking situation. Crossed-adaptation experiments, in which the acoustic information shared by the adapting stimulus and the test utterance is varied, will be conducted to determine some of the operations performed by the perceptuo-motor component of the speech system. The present acoustical studies will aid in formulating a more detailed neural model of perceptuo- motor component of the speech system. The present acoustical studies will aid in formulating a more detailed neural model of perceptuo-motor control in speech. In addition, the studies will provide useful guidelines for further experimentation in which the role of laryngeal factors such as glottal width can be directly assessed.